1. Field Of the Invention
The invention relates to a process for the laser treatment of the inside surfaces of hollow pluralities with rotation-symmetric axes, which consist of a matrix alloy.
More specifically, this invention relates to the laser treatment of light metal engine cylinder blocks to provide a wear-resistant inner piston working surfaces. Furthermore, the invention relates to a device for carrying out such a process.
2. The Prior Art
It is known, for example from German Patent DE 3910098 A1 to weld pipes by means of a laser, whereby a rod-shaped probe with a lens system is disposed in a workpiece. In laser surface treatments, it is advantageous to also treat marginal surface coatings, especially on the inside of the workpiece, by the application of laser energy over wide surface areas.
Thus, it is an object of the invention to obtain increased amounts of alloying components in marginal coatings, as well as intermetallic compounds in these coatings, and to obtain a finer grain coating in the marginal layer, particularly in connection with cast aluminum or wrought alloys.
It is a further object of the invention to provide an increased resistance to abrasion in metallic materials, such as in engine block components and also in tools subject to wear, as well as in tubes and guide bushings.
In the prior art, wear-resistant workpieces were produced by alloying the entire material of the workpiece with an additional substance, such as, adding up to 17% silicon to an aluminum cast alloy. Where the surface is to be provided with higher wear resistance, the silicon coating provides a wear hardened surface. However, this makes the overall workpiece more brittle, which leads to substantial problems in the casting process.